Imine-terminated polymers improve cotton durable press products

ABSTRACT

Imine-terminated polymers having polyalkylene ether moieties with a molecular weight between 500 and 10,000 have been used to improve the wet and conditioned wrinkle recovery and smoothdrying characteristics of cotton fabrics. Durable press performance can then be achieved by treatment with said polymers in combination with a less than usual amount of cross-linking agent. Such a system produces a fabric with higher conditioned and wet wrinkle recovery and better breaking strength, tearing strength, and abrasion resistance than conventional treatment. These polymers also have been used in combination with preferential cross-linking and wet fixation methods to produce fabric with improved wrinkle recovery and increased abrasion resistance.

United States Patent Bruno et a1.

[ 1 Feb. 1,1972

Harper, Jr., Metairie; John D. Reid, New Orleans, all of La.

[73] Assignec: The United States of America as represented by the Secretary of Agriculture [22 Filed: May 13, 1969 211 Appl.No.: 824,252

8/115.6 [51] Int. Cl. ..D06m 13/48, D06m 13/54, D06m 13/34 [58] Field of Search ..8/116.2, 120, 116.3

[56] References Cited UNITED STATES PATENTS 3,523,750 8/1970 Tesoro ..8/l16.2

3,516,781 6/1970 Pensa et a1 ..8/l16.3

Primary Examiner-George F. Lesmes Assistant Examiner-J. Cannon Attorney-R. Hoffman and W. Bier [57] ABSTRACT lrnine-terminated polymers having polyalkylene ether moieties with a molecular weight between 500 and 10,000 have been used to improve the wet and conditioned wrinkle recovery and smooth-drying characteristics of cotton fabrics. Durable press performance can then be achieved by treatment with said polymers in combination with a less than usual amount of cross-linking agent. Such a system produces a fabric with higher conditioned and wet wrinkle recovery and better breaking strength, tearing strength, and abrasion resistance than conventional treatment. These polymers also have been used in combination with preferential cross-linking and wet fixation methods to produce fabric with improved wrinkle recovery and increased abrasion resistance.

3 Claims, No Drawings iMlNE-TERMINATED POLYMERS IMPROVE COTTON DURABLE PRESS PRODUCTS A nonexclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the Unites States of America,

This invention relates to the treatment of cellulosic materials with an imine-terminated polymer having a polyalkylene ether moiety. Particularly, this invention relates to an improvement of certain physical properties of cotton and other cellulosics which are treated with a cross-linking agent to produce wash-wear or durable press characteristics. More particularly, the amount ofcross-linking agent required can he reduced 50 percent to achieve adequate wash-wear or durable press performance. The process of this invention finds utility in the fabrication of wash-wear and durable press garments.

The main object of the instant invention is to provide a new and improved method for treating cotton textiles to impart wash-wear or durable press properties to the finished garment, or the like.

A second object of the instant invention is to provide durable press garments with improved abrasion resistance.

A third object of the instant invention is to provide improved breaking and tearing strength on durable press garments.

A fourth object of the instant invention is to provide a desirable hand to cotton durable press garments.

In the prior art we find that Harper, et al. disclose in Textile Industries, May 1967 a process wherein cotton fabrics are treated with polyacrylates to impart abrasion resistance, wrinkle recovery, and breaking strength. The cotton textiles treated by the said process made the fabric stiff and unsuitable for garment use unless the polyacrylates were used with a softening agent.

where R is a polytalkylene ether) glycol moiety, and n is equal to the number of these groups required to bring the molecular weight of this polymer to the preferred weight. For our purpose the preferred polymer is one with a molecular weight in the range of 500 to [0,000. Theoretically the cellulosic derivative would have structural formula represented thusly:

-i cm it The ingredients of our formulation require no additional softeners. The cellulosic derivative produced by the process of our invention contains a built-in softener.

In the process of investigation that led to the instant invention we have learned that unlike the textile products produced by processes of the prior art the textile testing results obtained have been in many instances inverse to the expected. For example, where in the prior art the tearing and breaking strengths have been decreased as the wrinkle recovery angles have been increased, in the instant invention we have tearing and breaking strengths which have been increased as the wrinkle recovery angles have been increased. Other physical characteristics have likewise been altered by the process of the instant invention. For a closer study of these results we call attention to Table I.

TABLE I. CO'ITON PRINTCLOTH TREATED WITH IMINE-TE RMINAIED 1 Polymg applied by emulsion method.

Polyurethanes were applied to cotton by Blanchard, et 211., as disclosed in Textile Industries, Jan. 1967, a process which also improves the physical properties of textiles and likewise made the treated fabrics stiffer.

The problem of stiffness in this prior art has been solved by the application of softeners, such as silicones, which of course makes the process less efficient costwise and otherwise.

Now we have discovered a chemical process where the physical properties are enhanced without affecting the stiffness of the fabric. The process of the instant invention can be either a single or a two-step process. The single step process is useful for treating fabrics where the entire bath would be used, and no storage would be required for the chemicals. The twostep process would be more suitable for instances where a prepared emulsion would break upon extended storage, therefore separate storage of ingredients would be preferred.

The process of the instant invention is one involving the use ofimine terminated polymers of the general formula:

It can be seen in Table I that the polyether has a pronounced effect upon both types of wrinkle recovery. Pretreatments with the polymer, followed by the application of 6 percent dimethylolethyleneurea (DMEU) produced a printcloth fabric with 315 (W+F) conditioned wrinkle recovery, approximately 40 greater than fabric treated with DMEU only. The improvement in wet wrinkle recovery ranged from 5565, depending upon the level of polymer pretreatment. The maximum increase in both conditioned and wet wrinkle recovery occurs upon application of polymer without cross-linking agent to untreated fabric. In one such application by organic solvent, using 9 percent polyether in tetrachloroethylene, the conditioned wrinkle recovery was 262 (W+F) and wet wrinkle recovery of 265 representing increases of 65 and respectively over the corresponding values of the untreated control. The: softening action of the polymer is reflected in the improved tearing strengths of the polyether treated fabrics over the control treated with DM EU. This improvement is very high in view of the high level of conditioned wrinkle recovery achieved by the combination treatments of polymer and cross-linking agent. A tearing strength retention of 88 percent was achieved with the highest level of polymer treatment as can be seen in Table I. Also it can be seen that the fabric breaking strength improves as a function of the amount of polymer used in the treatment. ln Table l the warp breaking strength of cotton printcloth treated by the process of the instant invention increases from 29 pounds with percent polymer up to 35 pounds with a percent application. Although the DMEU-treated control shows a strength of 32.9 pounds, intermediate in this series, the significantly lower wrinkle recovery of the control must be deemed a compensating factor. I

A comparison of the treatments with comparable wrinkle recovery performance shows (Table ll) an improvement from to 42 pounds in breaking strength in one case and from 30 to 38 pounds in another case from the case of the polymer additive. Even for the examples in which equal amounts of DMEU were applied to the fabric, an improvement of 6 and 8 pounds in warp breaking strength occurred.

The emulsion was applied to a sample of 80x80 cotton printcloth by padding with standard techniques to a wet pickup of about 80 percent, dried l0 minutes at 60 C. (the sample had a dry add-on of8.0 percent), and then the solution containing the cross-linking agent and catalyst were applied to a wet pickup of about 80 percent. The fabric sample was then mounted on a pin frame to maintain the original dimensions of the untreated sample. The impregnated sample was then dried 7 minutes at 60 C., then cured 3 minutes at l60 C.

The finished sample was submitted to a selected group of textile tests. The significant improvements found among these are listed below in a comparative study. The treated sample had a weight gain of 8.5 percent.

TABLE IL-COTTON PRINTCLOTH TREATED WITH IMINE-TE RMINATED POLYETI-IER, DMEU. AND POLYEIHYLENE Treatments Wrinkle recovery Elmendorf (W+F) tearing Breaking Stoll flex Crosslinker strength strength abrasion Polymer polyplus 1% Cond., Wet, (W) (W) (W) other 1 PE 2 deg. deg. (g) (1b.) (cycles) None 2% DMEU 258 222 787 36 882 7% 2% DMEU 290 286 813 42 1728 None c .3. 4% DMEU 237 244 660 30 314 7% 4% DMEU 304 303 673 38 1337 None 6% DMEU 302 262 573 30 124 Untreated control 197 173 1053 51 1139 1 Applied dissolved in perchlorocthylene. Z Polyethylene. 7 a E W in Table 1 it may be observed that with increasing amounts 3O s l l C I of the polyether add-on the Stoll flex abrasion resistance im- Tests proves progressively until it is approximately 95 percent of I that of untreated cotton. This occurs in fabric with condi- 533 2 o Breaking Strength I314 lbs. 3...) tioned and wet recovery angles above 310 and with a high s p Abrasion 234 15 level of cross-linking agent (6 percent DMEU). With the Wrinkle Recovery 315 g e 274 EXAMPLE 1 POLY ETHER EMULSION TWO-BATH PROCESS An emulsion was formulated and the imine-terminated polymer having a polyalkylene moiety was dissolved in an organic solvent, then emulsified, was prepared containing the in dicated quantities of the selected ingredients.

Ingredient Quantity (.i of bath. by wt.)

(Mnnostenratc.

Atlas 6-2162) Water A cross-linking solution which would be suitable for crosslinking of the cellulose structure of cotton was prepared, containing a computed quantity of an acid-type catalyst, as follows:

Cross-linking agent Quantity (71 of bath, by wt.)

Dimcthylolethylenc urcn 6.0 Zn(N0;,) 6H=O 0.4 Water 93.6

(conditioned. W+F) In reference to the physical testing methods it should be pointed out that the Elmendorf Tearing Test carries an ASTM Designation of Method D 1 424-63; the Breaking Strength Test Designation is Method l682-64; the Stoll Flex Abrasion Designation is Method Dl -64T; and the Wrinkle Recovery Test Designation is 1295-6OT; these designations by the American Society for Testing and Materials, Philadelphia, Pa.

Example 2 A TWO BATH SOLVENT PROCESS The imine-terminated polymer having a polyalkylene moiety was dissolved in a selected organic solvent, the bath contained the indicated quantities of the selected ingredients.

ingredient OuantityU/i by wt.)

lmineterminated polyether Perchlorocthylcne 93 A second solution was prepared, this contained the crosslinking agent, the selected catalyst, and water. The formulation was prepared thusly:

Cross-linking agent Quantity/('4 by wt.)

Dimethylolethylene urea 4.0 Zn(NO '6H,O 0.4 Water 95.6

Application from organic solvents has been contemplated for modern textile plants which are capable of using organic solvents for processing textiles. For this reason, this particular sample was handled in this manner.

The first solution was applied to a cotton printcloth in conventional equipment but equipped with well-ventilated devices. The excess solution was removed to obtain a wet pickup of 120 percent. The wet impregnated textile was dried 7 minutes at 60 C., and the equilibrated textile was found to have gained 8.5 percent in weight.

The emulsion was then padded onto the uncured wet-fixed The treated dry sample was then impregnated with the 5 Q second solution, which contained the cross-linking agent and sample to a wet p'ckup 80 percerlt dried at 60 for 7 catalyst. The wet pickup obtained was 80 percent. The textile mmutes and cured at 160 for 3 mmutes' A Companso" of was then dried 7 minutes at C, and cured 3 minutes at selected tests for the standard wet fix process and the wet fix 160 C. The fabric sample was then water washed and allowed piocess ,modlfied wlth the polyalkylene ether Polymer is to dry. The weight gain computed from the untreated original cheated m table weight ofthe sample was labeled as total weight gain: 10 percent.

T 6 i m e t TABLE I[t.-APPLICA'IION OF IMINE-TERMINATEI.)

s lg i zi z gg 35mg were selected be POLYETIIER T0 WET FIXED connunov 1 5 Wrinkle recovery *M Fill Fill Stoll flex Sample 2 Results (loud, Wot, tear break abrasion Tests Sample 2 Control deg. deg. (55.) (ll).) (cycles) Uncured wet fixed fabric. 168 190 783 45. 8 467 gmcndmf Tum-mg Strength 813 787 Gigi-ed wet fixed fabric 236 211 417 2!). 0 .200 Breaking Strength 42 lbs. 36 2O gg g g gfi wet Stoll Flex Abrasion L728 cycles 882 fixed [abrie 'A 316 g 00 3 3 1 533 Conditioned Wrinkle 290 degrees 258 Recovery (warp fillin l Polymer applied from emulsion.

EXAMPLE 3 EXAMPLE 5 A SINGLE-BATH EMULSION PROCESS The imine'terminated polymer was formulated so as to in- WITH THE CROSS'UNKING AGENT clude the cross-linking agent, a selected catalyst, a wetting An lmme'termmated P clomamlflg formulauon w agent, an organic solvent, an emulsion stabilizer, and water, all Prepared for h first P comammg the Indicated quammes in the same bath. The bath contained the indicated quantities ofthe selected mgredlents' of the selected ingredients.

Ingredient ()uantityt't by wt. lngl'cdlenl lmine-terminatcd polyether l().0 QuantityU/r by wt.) n l0.0 Emulsifying agent 4.0 ZMNOHEGHZD 0.4 Dimethylolethylene urea 5.0 water zn No n-enp 0.5 timulsifying agent 3.0 lMonostearate. Atlas 0-2 I 62) vimmul 89) The emulsion was then applied to a sample of 6 02. cotton wining sateen, dried 7 minutes at 60 C., and weighed. auntie. 'lriton X-l00) 0.1 The dried impregnated textile was then given a back coating Polyelh" by the process described by Cooper et al. in the American 322' a]: Dyestulf Reporter, Vol. 54, page 89 (1965), using an aqueous formulation containing 0.8 percent ihydroxyethylcellulose (thickener) and 12 percent dimethylolpropyleneurea. This EXAMPLE 4 was applied to the back of the fabric to obtain a 30 percent INCORPORATING wn'n WET-FIXATION PCkUP a kmfebade To illustrate another embodiment of the instant invention A t cuff was Prepared from i s z and this an iminc-terminated polymer ofthe instant invention was used Submitted to a Standard. laundry testing proce The cu to supplement :1 wet-fixation process" described by Hollies thus prepared was Submmed to 20 Standard launqermg i and Getche in Textile Research J Vol 37 pp 7076 and was found to have lasted 18 cycles before minor abrasion (1967) The adaptation can be made to other kno wn wet-fixdamage was noted' The Wrinkle recovery zingle (warp plus ation pr'oCmseq as we filling) after the 20 laundering cycles was a suitable 260 C.

\FiXedY\ les rovided b a commercial textile m NOTE: When a sateen cuffwas prepared as in example 5v above. but increasing the p y dimethylolpropylene urea content to l5 percent and excluding the iminc-terusmg the Homes and Getche Procedure' These samples were minated polyether of this invention the results obtained were significantly unfurther processed by applying the imine-tcrminated polyether satisfactory. The wrinkle recovery angle evaluation was 243 after 20 laundering of our invention Requhs f comparative dy are Shown i cycles, and minor damage was noted at the end ofthe 9th cycle. Improved wrinkle bl H I recovery and abrasion resistance were imparted by the use of imine-tcrminated 1: e I I polyctherofthe instant invention.

Wet fixation IS a method of internal polymer deposition in which the fiber remains somewhat swollen during the polymer W l deposition step. The resultant fabric generally has good abra- 1 f H l sion resistance, but wrinkle recovery values obtained from h h h g 0T fl tzj l fi I a cottclm ce lJOiIIC ctextle mill finished fabric are frequently low. The imine-terminated F l t wlt fF T e z polymer improves the performance of wet-fixed fabrics in that e mes O tame m Crossm mgt e Ce ose out lower than normal wrinkle recovery angle can be raised to the Wrinkle recovgiy losses generally associated with Such durable press performance. F compnsmg' A single bath emulsion formulation was prepared thusly: a. impregnating the dried, wet-fixed cotton cellulosic textile '70 with a single bath emulsion containing about 17 percent 1 O n (I b benzene, about 4 percent monostearate emulsifying W y I agent, about 0.4 percent of an acid catalyst selected from the group consisting of zinc nitrate lhexahydrate catalyst g 'l 5'8 and magnesium chloride hexahydrate, about 61.6 percent C .n' i g l (emulsirving water, and about 17 percent of an imme-terminated itgtinl) 4.0 polymer having the formula wherein R is a poly(alkylene ether) glycol moiety and n is equal to the number of these groups required to bring the 

2. The process of claim 1 wherein the catalyst is zinc nitrate hexahydrate.
 3. The process of claim 1 wherein the catalyst is magnesium chloride hexahydrate. 